1
Q
What are the 3 tectonic hazards and explain:
A
- Volcano - a landform that develops around a weakness in earths crust from which molten magma, disrupted from pre-existing volcanic rock, and gases are ejected.
- earthquake - shockwaves created by the release of tension at a focal point
- tsunami - a sequence of huge waves created by a large displacement of seawater, usually by undersea earthquake.
2
Q
What are 2 ways of classifying tectonic hazards and give an example of each
A
- primary - eg. earthquakes and volcanos
-secondary - eg. tsunamis (happen as result of primary hazard)
3
Q
Definition of natural hazard:
A
- a naturally occurring process or event that has the potential to affect people.
4
Q
Definition of a natural disaster:
A
a major but natural hazard that causes significant socioeconomic and environmental damage.
5
Q
Definition of vulnerability:
A
the ability to anticipate, cope with, resist and recover from a natural hazard.
6
Q
Explain the distribution of tectonic hazards:
A
➔ Geophysical hazards occur near plate boundaries. These plates move at different speeds and directions which can cause collisions, earthquakes and volcanic activity.
➔ Earthquakes can also occur near the middle of plates (called intra-plate). The causes of this are not fully understood but it is assumed that plates have pre-existing weaknesses which become reactivated, forming seismic waves. For example, an intraplate earthquake may occur if solid crust, which has weakened over
time, cracks under pressure.
➔ Volcanic hotspots, such as the Ring of Fire, are also situated amongst the centre of pates. This is a localised area of the lithosphere (Earth’s crust and upper mantle) which has an unusually high temperature due to the upwelling of hot molten material from the core. (First theorised by Tuzo Wilson in 1963)
➔ At hotspots, such as the Hawaii hotspot, magma rises as plume (hot rock).
➔ Usually, the most powerful earthquakes occur at convergent or conservative boundaries
.
OFZ (Oceanic Fracture Zone) – This is a belt of activity through the oceans and along the mid-ocean ridges through Africa, the Red Sea, the Dead Sea
CFZ (Continental Fracture Zone) – This is a belt of activity along the mountain ranges from Spain through the Alps to the Middle East and to the Himalayas.
7
Q
Where are most earthquakes found/ distributed?
A
About 70% of all earthquakes are found in the “Ring of Fire” in the Pacific Ocean. The most powerful earthquakes are associated with convergent or conservative boundaries, although rare intra-plate earthquakes can occur. This distribution of earthquakes reveals the following pattern:
The oceanic fracture zone (OFZ) – a belt of activity through the oceans along the mid-ocean ridges, coming ashore in Africa, the Red Sea, the Dead Sea rift and California
The continental fracture zone (CFZ) – a belt of activity following the mountain ranges from Spain, via the Alps, to the Middle East, the Himalayas to the East Indies and then circumscribing the Pacific
8
Q
What model shows when a natural hazard becomes a disaster? (17/1/25)
A
Deggs model
9
Q
What are tectonic plates?
A
- large irregularly shaped slabs of rock that vary in size and move slowly.
10
Q
What is the lithosphere?
A
Earth’s surface layer, made up of the crust and upper mantle, broken into sections with average depth of 100km.
11
Q
What is the asthenosphere?
A
The liquid part of mantle that allows some movement of mantle.
12
Q
What are the 4 types of plate movements?
A
- convection
- slab pull
- ridge pull
- subduction
13
Q
Explain convection:
A
Convection in the mantle was thought to cause plate movement, but is now less accepted. heat from the decay of radioactive elements in the core heats the lower mantle - creating convection currents. These hot magma (molten rock) currents are thought to circulate in the asthensophere, causing plates to move.
14
Q
Explain slab pull:
A
slab pull is seen as a driving force for plate movement. Newly formed oceanic crust at mid-ocean ridges becomes denser and thicker as it cools. This causes it to sink into the mantle under its own weight - pulling the rest of the plate with it.
15
Q
Explain ridge push:
A
As the lithosphere which is formed as divergent plate margins is hotter and less dense than the surrounding area, it rises to form oceanic ridges. These ridges then slide sideways away from these high areas, pushing the plate in front of them. This results in a ridge push mechanism. This movement is enhanced by slab pull.
16
Q
Explain subduction:
A
As crust is created in one place, its destroyed in another- by subduction. As oceanic plates (or oceanic plate and continental plate) meet, one slides under the other into the mantle - where it melts in a subduction zone. Slab pulls is the other driving force, pulling other slabs under gravity to the subduction zone.
17
Q
Look at page 7 of textbook figure 2 to see the mechanisms of crustal movement - ridge push and slab pull
A
18
Q
What is a plate boundary?
A
when two tectonic plates meet.
19
Q
What are plate margins?
A
The areas adjacent to plate boundaries and areas either side of the boundary that may be affected by movement.
20
Q
What are the 3 types of boundaries and explain:
A
- convergent - where two plates collide also known as destructive margins
- divergent - where two plates move apart, also known as constructive margins
- conservative - where two plates slide past each other, also known as transform margins
21
Q
What are the 3 types of destructive plates margins and explain:
A
- Continental-oceanic - Oceanic plate is denser than continental so as they collide oceanic plate slides beneath continental into mantle and melts. Deep ocean trenches occur when oceanic plates start to sink under continental. This subduction leads to formation of fold mountains (as two plates collide, continental plate is folded and pushed up, forming fold mountains. Since plates are constantly moving, fold mountains continue to grow. Friction between colliding plates (and resulting subduction) causes intermediate and deep earthquakes in area called Benioff zone. Volcanic eruptions are generated as magma created by melting oceanic plate pushes up through faults in the continental crust to the surface - causing explosive eruptions. Destructive plate margins are the most seismically active areas of hazards.
- Oceanic - Oceanic - When two oceanic pates collide, the denser or faster is subducted beneath the other. Deep ocean trenches form, and subducted plate melts - creating magma, which rises from Benioff zone to form underwater volcanoes. These can rise above sea level to form seperate island volcanoes, usually found in island arcs. Subduction also produces shallow-to deep-focus powerful earthquakes. The 2004 Indian Ocean tsunami was caused by earthquake where two oceanic plates collided.
- Continental - continental - When two continental plates meet, a collision margin occurs. As both plates have similar density, neither is actually subducted. Instead, they collide and sediments are crumbled and forced up to form fold mountains. Some subduction can occur when compressed denser sediments result in plate subduction. Any earthquakes are likely to have shallow focus - increasing severity.
22
Q
What two things do constructive plate margins form and explain:
A
- as constructive plate margins, two plates move apart, which leads to the formation of new crust. In oceans, this forms mid-ocean ridges and on continents it forms rift valleys.
- Mid-ocean ridges - Breaks called transform faults cut across these ridges as they spread at different rates. Shallow focus earthquakes occur, but pose little risk because shocks are minor and occur underwater. Regular eruptions create submarine volcanoes, some of which grow above sea level to create islands.
- Rift valleys - When plates move apart on continents, the crust breaks into sets of parallel cracks (faults). The land between these faults collapses, forming steep sided rift valleys.
23
Q
Explain what happens at a conservative plate margin:
A
- along some boundaries, two plates slide past each other, forming a conservative plate margin. This results in a major break in the crust as they move. This break is called a fault and on a large scale is known as a transform fault, which affects wider area. Although no crust is made/destroyed this type of margin is tectonically very active and is associated with powerful earthquakes. The plates sometimes stick as they move, causing stress and pressure to build up which is released as a strong shallow-focus earthquake.
24
Q
Where are most volcanoes and earthquakes located?
A
- along plate margins
25
If a volcano/earthquake doesn't form along a plate margin where would it form?
Intra-plate earthquakes- occur rarely in the middle of plates, far from plate margins. A series of violent earthquakes (magnitude 7.4-8.6) occured in the New Madrid seismic zone in Missouri, USA during 1811-12.
26
When do earthquakes become and hazard?
when people are involved as these events can cause mass death and destruction.
27
what % of earthquake occur along tectonic plate boundaries and why?
95% of earthquakes occur along tectonic plate boundaries - as plates move they stick, allowing pressure to build which is released in powerful seismic waves from fault lines.
28
Explain how earthquakes form:
- result of pressure caused by extreme stress in earths crust
- When plates try to move, there is build up of pressure
- This releases by seismic waves and the stress causes cracks in the crust which causes earthquakes.
29
Definition of seismic waves:
energy waves that ripple out from the focus/hypocentre.
30
Definition of primary (P) waves:
longitudinal waves that push out from the focus (slinky movements)
31
Definition of secondary (S) waves:
Transverse waves that 'shake' through the crust and mantle from the focus.
32
Definition of love (L) waves:
Surface waves that 'flow' over surface from epienter.
33
How do we measure earthquakes?
- seisometer - detects ground movement.
34
what does a earth scientist use to measure earthquakes?
- magnitude
- intenstity
35
look at sheet 7/2/25 for more info on earthquakes
36
name and explain 2 primary effects of an earthquake and what they cause:
1. Ground shaking - buildings, bridges, roads and infrastructure to collapse - killing/injuring those nearby
2. crustal fracturing - when energy released during an earthquake causes earths crust to crack.
37
name and explain 3 secondary effects of an earthquake and what they cause:
1. liquefaction - the violent shaking during earthquake causes surface rocks to lose strength and become more liquid than solid. The subsoil loses its ability to support building foundations, so buildings and road tilt or sink.
2. landslides/avalanches - ground shaking places stress on slopes, so they fail, resulting in landslides, rock slides, mudslides and avalanches. They account for a large proportion of the damage and injuries caused by an earthquake.
3. tsunami - some underwater earthquakes generate tsunami that cause major problems to coastal areas.
38
Explain why geology was an important factor in the destruction and deaths during the Loma Preita earthquake (North California)
- the soil and sand it was built on was soft , sandy soil.
- Marina district - suffered from liquefaction.
- part of motorway collapsed - caused 42 of the 67 deaths - built on soft mud.
- areas on firmer ground remained standing.
39
What are aftershocks?
- weeks, months or even years after and earthquake other smaller earthquakes like aftershocks may follow.
-This is due to a realignment of the fault.
40
Why are aftershocks dangerous? give an example (ao1)
- they can cause additional damage
- structures weakened by the original earthquake may collapse.
- eg the 2011 magnitude 6.3 aftershock that struck Christchurch (new Zealand) caused more damage and loss of life than the initial 2010 earthquake.
41
What are intra-plate earthquakes?
- occur in the middle of plates- far from margins.
- may be from ancient faults where pressure has previously built up.
- much harder to predict
- fracking also causes earthquakes - the water lowers the stress level needed for ground slippage.
42
What are landslides and give an example of the effect of this (ao1)
- occur when slopes weaken and fail, can collect material making them a destructive landform.
- occur in mountainous areas and can be made worse by monsoon rainfall.
- eg. during 2005 Kashmir earthquake, landslides caused 1/3 of all deaths.
43
What are volcanoes?
- openings in the earths crust through which lava, ash and gases erupt.
44
What are the 3 main types of lava which can be erupted:
- basaltic (hottest)
- andesitic
- rhyolitic (coolest)
45
What are the two types of volcano?
1. gentle fissure
2. explosive composite
46
What does the shape of a volcano reflect?
type of lava erupted
47
Give a case study example of Volcanoes:
2010 Iceland volcanic eruption - Eyjtjakajokull
48
Give some impacts of the Eyjtjakajokull volcano:
- 100,000 commercial flights cancelled worldwide
- 10 million passengers
- Airlines lost $1.7 billion in revenue
- 75% European air capacity was cut
49
Why was the Eyjtjakajokull volcano so explosive?
- it is covered with an ice sheet, so when magma hit ice it superheated into steam.
50
What were the economic effects of the Eyjtjakajokull volcano?
- 20% of Kenya's economy comes from vegetable exports to Europe.
- With flights cancelled, Kenya was forced to dump vegetables and lost $1.3 million a day in revenue.
51
What are the 4 primary hazards of volcanoes and explain:
- lava flows - streams of lava that can reach 1170 degree, generally move slowly (decrease risk)
- Pryoclastic flows - dense rock, lava, ash and gas at 700 degrees and move at 100km/hour (increase risk)
- Tephra and Ash falls - pieces of volcanic rock blasted into the air. Ash can travel thousands of km causing poor visibility as it falls. Roofs can collapse from weight of ash.
- Gas eruptions- dissolved gases in magma are released into atmosphere (co2, so2)
52
What are the 2 secondary hazards of volcanoes and explain:
- Lahars - rock, mud and water masses that travel quickly down the sides of a volcano - these can be hundreds of meters wide and flow at tens of meters per second.
- Jokulhlaup - heat of volcanic eruption melts snow and ice causing sudden floods.
53
What is the 2nd case study for volcanoes and how did it happen?
- Montserrat - 18th July 1995
- Montserrat soufriere hills started to smoke.
- eruptions continued for 5 years after with pyroclastic flows covering much of the island.
- two oceanic plates submerged - denser one subducted.
54
What were the impacts of the Montserrat volcano?
- 7000 people moved to other countries
- The capital Plymouth - destroyed
- 2/3rds of all houses - destroyed
- unemployment rose from no tourism
- agriculture was severely affected
- young people left and older people stayed.
55
How do you measure volcanic eruptions?
- using volcanic explosivity index (VEI)
- from 0 (non-explosive) to 8 (extremely large)
- It is a logarithmic scale that uses the following:
- amount and height of volcanic material ejected (temphra ash fall)
- how long eruption lasts
- qualitative descriptive terms (eg. gentle, explosive)
56
What do we predict volcanic eruptions?
- small earthquakes - indicating movements within plates
- volcano tilt change - can use tiltmeter
- surface changes - magma moving in/out of volcano deforms surface.
57
How are tsunamis caused?
- By large underwater earthquakes along subduction zones (two oceanic plates meeting).
- Energy released during the earthquakes causes the sea floor to uplift - causing a ass of energy displacing the water vertically upwards.
- Gravity pulls it back down causing the waves to carry on towards the shore.
- When the water gets shallower the wave still has all the energy.
- This displaced water forms the tsunami wave.
58
What are the impacts of a tsunami?
- Tsunamis can travel for many km inland - sweeping away buildings, trees, bridges and people.
- Tsunamis also wash away soil - can undermine foundations of buildings and transport connections as well as destroying farmland.
- small islands can be entirely washed away.
- Most tsunami -related deaths = drowning or collapse building
- water can also be easily contaminated - lead to cholera.
59
Give a case study 1 on tsunamis :
2004 Indian ocean tsunami
60
Give the impacts of the case study 1 (2004 Indian ocean):
- $10 billion in damage
- In Sumatra 1500 villages were completely destroyed
- In Sri Lanka more than 60% of fishing and industrial infrastructure were destroyed.
- saltwater contaminated agriculture and freshwater supplies.
61
What were the effects on other countries after tsunami 1 (2004 Indian ocean)
- 15 mins after earthquake Sumatra was hit (worse affected area)
- 60 minutes after, Malaysia hit
- 90 minutes after, Tailand hit - 1000 tones water hitting coast full of tourists
- 120 mins after Sri Lanka hit.
62
Explain why countries closest to the Epicentre were worse affected by tsunamis?
Because the wave has the most energy and is therefore more destructive at the epicentre.
63
Give case study 2 on tsunamis and give some context:
- 2011 Tohoku tsunami (Japan)
-The 2011 Tohoku tsunami was the most costly hazard (not just tectonic) to affect our planet.
-Part of this was due to the strength of the earthquake; so powerful that it:
Shifted the main island (Honshu) 2.4m East
Shifted the Earth’s axis between 10cm and 25cm
Increased the Earth’s rotation speed by 1.8 microseconds
64
What were the causes of the 2011 Tohoku (Japan) tsunami
- seabed off the eastern coast of Japan is a highly seismologically active section of the earths crust.
- Eurasian, pacific and Philippine plates meet here, making it an extremely complex boundary.
- Japan located on the eastern edge of Eurasian plate, adjacent to the huge, very solid pacific plate.
- Pacific plate - moving westwards, towards Eurasian.
- as denser of the two, the pacific plate dips beneath.
- Wednesday 9th March 2011 saw a 7.2 earthquake on plate boundary- knock - on effects were particularly serious, as push of pacific plate as it went under Japan - put extra strain of area existing pressure build up along plate margin.
65
How do we predict tsunamis?
- difficulties predicting tsunamis
- early warning systems - sensors can detect prolonged changes in wave height near coastal areas.
- These connect to satellites and can warn countries of approaching tsunamis
- DART (deep ocean assessment and reporting of tsunamis) - allows alarms and texts to be sent asking for evacuations.
66
Definition of vulnerability:
the ability to anticipate, cope with, resist and recover from a natural disaster.
67
Definition of resilience:
The ability to protect lives, livelihoods and infrastructure from destruction, and to restore areas after a natural hazard has occured.
68
Definition of tectonic event:
A natural hazard - earthquake, volcanic eruption or tsunami.
69
Definition of disaster:
a serious disruption of the functioning of a community, involving widespread human, material, economic or environmental losses and impacts, which exceeds a community's ability to cope.
70
Whats the equation for risk?
risk (R) = hazard (H) x vulnerability (V)
-------------------------------------------
capacity to cope (C)
71
What are the factors that impact the risk of a country of natural hazards?
- exposure score - Italy has a moderate natural hazard component as it lies on a plate boundary and experiences frequent earthquakes (7 major ones between 2012 – 2017)
- Vulnerability - Moderate vulnerability. Large areas are mountainous and it has an ageing population. Old infrastructure increases risk.
- coping capacity - Coping capacity is good. Italy is a developed country, located in close proximity to other developed nations
- Overall risk -Italy ranks as 142nd (1st is worst), thanks to it’s common drills, governance and moderate coping capacity
72
What are some of the factors that increase vulnerability?
- corruption- government
- urbanisation- buildings, higher density, infiltration
- Health care - bad = death toll increase
- high pop density - more people at risk
- wealth- LIC- less protection +predictions- longer recovery
- housing - weak materials = more destruptions
- Access to education/public education - children taught how to be safe in hazard
- Communication systems - ability to predict and warn people to evacuate
73
What are the 3 countries we studied for their tectonic risks, what years were they in and were they developed/developing/emerging?
- Haiti - 2010 - developing
- China - 2008 - emerging
- Japan - 2011- developed
74
What were the type of hazards and preparations of the 3 hazards:
- Haiti (2010, developing) -
TYPE- magnitude 7.0, 250,000 dead, 300,000 injured, 1.3 million homeless, $14 billion damage.
PREP - limited resources being spent on more immediate issues - disease rather than prep, high level corruption - led to lack of resources to improve infrastructure, lack of prep emergency services didn't know what to do when emergency struck, many Haitians living in poverty - don't have resources to prepare/ cope with effects.
- China (2008, emerging) -
TYPE - 7.9 magnitude, 87,150 dead, 375,000 injured, 5 million homeless, $126 billion damage
PREP - corrupt gov, accepted bribes for builders to take shortcuts poorly constructed buildings, after investing in safer buildings and better infrastructure and has resources to respond quickly.
-Japan (2011, developed)
TYPE - 9.0 magnitude, 19,848 dead (tsunami), 6065 injured, 130,927 million homeless, $240 billion damage
PREP - tsunami caused by earthquake reached 10m high, surged 10km inland, power - plant damaged - released dangerous levels of radiation, 47,000 evacuated.
75
How were the 3 places (Haiti, China and Japan) vulnerable to their hazards?
- Haiti (2010 - developing) - limited resources, corrupt gov where building regulations are poor, lack of disaster prep.
- China (2008 - emerging) - China could afford rescue efforts and a fast response to the disaster
- Japan (2011- developed) - strict building regulations mean 75% of all buildings in Japan are earthquake proof, early warning systems urged evacuation, early earthquake drills and very well educated population for hazards.
76
How did the 3 places (Haiti, China and Japan) respond to their hazards?
- Haiti (2010 - developing) - $13 billion in aid (but only 10% was in the control of the Haiti government, 2015 - 80,000 still in temp shelters, government destroyed so acceptance of aid was slow.
- China (2008 - emerging) - 130,000 soldiers started search and rescue within hours, $10 billion pledges for rebuilding, 97/5 of reconstruction complete within 2 years
- Japan (2011 - developed) - 110,000 troops mobilised in the first 24 hours, $183 billion from Bank of Japan given to keep economy going in local areas, help accepted from other countries
77
What is the pressure and release (PAR) model?
identifies the root causes, dynamic pressures and the unsafe conditions that can lead to a hazard becoming a disaster.
78
What are the root causes, dynamic pressures and unsafe conditions?
- root causes - input
- dynamic pressures - process
- unsafe conditions - output
79
What is the pressure and release model for Haiti (developing)
-root causes/input - heavily in debt to US, German and French banks, 80% of people live off $2 a day
-dynamic pressures - process - lack of money spent on disaster planning and management systems, rapid urbanisation
- unsafe conditions - output - buildings were poorly constructed in cheap and rapid conditions creating vulnerable structures, 39% of the population had access to clean water
80
What is the pressure and release model for China (emerging)
-root causes/input - corruption in Chinese gov meant building codes were ignored and shortcuts taken, school buildings poorly built while gov buildings remained intact.
-dynamic pressures - process - a lack of urban planning and poorly built houses.
- unsafe conditions - output - poorly built houses meant that 1/4 of earthquake related deaths were due to landslides and buildings collapsing.
81
What is the pressure and release model for Japan (developed)
-root causes/input - Fukishima power plant built by authorities in hazard zone.
-dynamic pressures - process - a lack of urban planning, buildings and marine supplies not prepared for nuclear waste in event of natural hazard
- unsafe conditions - output - Fukishima nuclear accident contributed to 2000 of the death toll.
82
Why do high income countries sometimes suffer more than low income
They are more able to report official death statistics and will suffer higher economic costs.
83
What are the human factors affecting vulnerability at a local scale?
- education - those less educated may be less aware of the risks of a hazard event and how to protect themselves.
- housing - poor quality housing less able to withstand natural hazards.
- healthcare - communities with poor healthcare suffer from disease.
- income - lack of income opportunities means that people cannot buy resources they need.
84
How did human dynamic factors influence their vulnerability during 2010 earthquake?
- population- 10.2 million people
- GDP per capita - $1,179
- life expectancy at birth - 62.1 years
- education -bad - 4.9 years - mean years of schooling
- corrupt government
85
Explain why Japan has a better capacity to cope than Haiti
Japan is more developed than Haiti, therefore they have better income opportunities to help them prepare for hazards. This overall increases their capacity to cope. Haiti also has no global partnerships.
86
What are hazard profiles?
used to help with disaster plans by governments and organisations.
87
What are the limitations of using hazard profiles?
- no single organisation is responsible for collecting data
- there are not clear standard for what to gather
- when disaster strikes immediate efforts go into rescue not data.
88
What are the 6 physical dynamic factors?
1. Magnitude
2. Speed of onset
3. Duration
4. Areal extent
5. Predictability
6. Frequency
89
Explain the 6 dynamic factors?
1. Magnitude - scale/intensity of tectonic hazard --> amount of tension/power of hazard.
2. Speed of onset - how quickly the hazard occurs/felt by population.
3. Duration - how long the hazard lasts.
4. Areal extent - how widespread/ how big effected area is.
5. Predictability - the ability to know if a hazard is coming.
6. Frequency- how often the hazard occurs.
90
How do the 6 physical dynamic factors affect severity?
1. Magnitude - higher magnitude, increased severity.
2. Speed of onset - higher speed, the increased severity - less time to prepare = more damage
3. Duration - the longer the hazard the more chance for damage
4. Areal extent- greater area effected = greater damage
5. Predictability - more frequent - greater risk but overtime more prepared as educated.
6. Frequency
91
What are the 5 tectonic events we have studied?
1. Bam, Iran - 2003
2. L'Aquila, Italy - 2009
3. Haiti - 2010
4. New Zealand - 2010 + 2011
5. Nepal - 2015
92
What were the causes to the tectonic events we have studied?
1. Bam, Iran - 2003 - Arabian plate moving 2.5cm per year in relation to Eurasian plate, 6.6 magnitude EQ
2. L'Aquila, Italy - 2009 - Magnitude 6.3 EQ, duration of 30s, on border of African and Eurasian plate
3. Haiti - 2010 - on border between NA and Caribbean plate, level 9 Mercalli, 65km rupture zone
4. New Zealand - 2010 + 2011 - Border of Australian and Pacific plate, 6.3 magnitude EQ, 5km depth, 6km SE Christchurch
5. Nepal - 2015 - collision between Eurasian and Indian plate, 4.5cm of movement per year, Kathmandu valley raised 1m
93
What were the dynamic factors to the tectonic events we have studied?
1. Bam, Iran - 2003 - no major EQ in 2500 years, Iran very closed off since 1979 Iranian revolution, low supplies by government
2. L'Aquila, Italy - 2009 - Epicentre directly on L'Aquila, mountainous area, so many landslides, occurred middle of night
3. Haiti - 2010 - GNI per capita of only $660, 2.2% of population has HIV/AIDS, poor building codes, set by government
4. New Zealand - 2010 + 2011 - second large EQ in 5 months, developed country, $10bn set aside, mid-afternoon
5. Nepal - 2015 - total of 300 aftershocks, Kathmandu valley on 300m of clay, heavily reliant on agriculture, women in houses
94
What were the impacts to the tectonic events we have studied?
1. Bam, Iran - 2003 - 30,000 people died including 11,000 students, 26,200 injured, destroyed underground water stores
2. L'Aquila, Italy - 2009 - 65,000 homeless, 15,000 buildings destroyed, EQ resistant hospital closed due to damage
3. Haiti - 2010 - 230,000 deaths, after 6 months, 1.6m still in camps, 70% of buildings collapse (including 8 hospitals and the port)
4. New Zealand - 2010 + 2011 - $20bn damage, 185 people killed, 40% of buildings damaged beyond repair
5. Nepal - 2015 - 9000 people died, thousands evacuated due to flooding, 90% of tourists bookings cancelled, 33% of total GDP damage done
95
What are the reasons why there may appear to be more disasters?
- improvements in monitoring and recording events
- improvements in technology and media reporting
- population increase
- increase in proportion of earth covered by humans
- increased urbanisation
96
Why have hydro-meteorological hazards been increasing?
due to climate change and cost of damage done has been increasing as more countries develop.
97
What are multi-hazard zones?
locations where you are at particularly high risk of experiencing hazards (both meteorological and tectonic)
98
Where are multi-hazrad zones mainly found?
99
What case study did we use for a multi-hazard zone?
Philippines
100
Why is the Philippines a multi-hazard zone?
-sits across a major convergent plate boundary - faces significant risks from volcanoes and earthquakes
- North and Eastern coast - face pacific ocean (worlds most tsunami prone ocean)
- Landslides common due to steep topography
- high levels of deforestation and rainfall
- Philippines is on western rim of 'pacific ring of fire' - brings both earthquake and volcanic activity
- Lies within South- east Asia's major typhoon belt.
-climate = tropical monsoon - subject to heavy annual rainfall.
101
Name some of the Phillipines most frequent hazards and give details:
- floods - total = 161
total deaths: 3814
- storms and typhoons = 333
total deaths: 45,040
-landslides = 31
total deaths: 2469
102
Name some of the Philipines most infrequent hazards and give details:
- Tsunami - 1
total deaths: 32
- Droughts - 10
total deaths : 8
- Volcanos -25
total deaths: 1078
103
What is the Philippine's capacity to cope?
- middle income country- GDP per capita US$8893 in 2021
- high population - 101 million
- Philippines is a rapidly developing lowe-middle income country - development and fast-growing population has led to rapid urbanisation and high pop density
- many of poorer areas live in coastal areas - where sea surges and flooding/tsunamis made worse by poorly constructed housing and infrastructure
- 2021 - 18% lived in poverty
104
What are the challenges of living in a multi - hazard zone with an example:
- one hazard event can cause or increase other hazards: eg. earthquake in Philippines 2006:
- killed 15 people, injured 100 and damaged/ destroyed 800 buildings
- generated local tsunami - 3 metres high
- triggered landslides - breached the crater wall of volcano and fell into lake, creating flood - washed away houses
105
What is forecasting?
The specification of the probability of an earthquake occurring at a given location, time window, and magnitude range
106
What is the hazard management cycle?
A process in which governments and organisations work together to protect people from the natural hazards that threaten their communities.
107
what are the aims of the hazard management cycle?
-Avoid loss of life
-Reduce property damage
-Provide help for people affected
-Ensure effective recovery
It involves governments, businesses and community groups
108
what are the 6 risk reductions?
- Disaster response
- Disaster recovery
- Disaster mitigation
-Development
-Adaption to change
-Disaster preparedness
109
Look at 25/4/25 for diagram of hazard management cycle (page 38)
110
what is the Park model?
shows the potential rebound of a country after a disaster.
111
Look at 25/2/25 for Park model diagram (page 39)
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What are the 4 different ways events can be managed?
- land-use zoning - government planners regulate land use. Areas most susceptible to lava flows are avoided. Structures prone to damage are limited. eg. nuclear plants.
- Directing lava flows - barriers and changes can be used to divert lava flows into safer directions away from communities/industries. Historically these have been ineffective but was possible with Mt Etna in 1983.
- Hazard resistant design and engineering - collapse buildings is one of main causes of death and damage from tectonic hazard. Sloped roofs near volcanoes can reduce ash build up. Buildings and designs can resist ground shaking impacts. Protective structures such as seawalls and levees can assist with protecting from tsunamis.
- GIS mapping - can be used in all stages of hazard management cycle - can identify evacuation routes or areas being affected - can also assist in directing response teams.
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who are the key players in managing loss?
(look at more info 9/5/25 sheet)
- aid donors: emergency, short -term and long-term aid. Aid can be cash services, personnel or equipment. Aid can be: governmetal, intergovernmental or NGOs.
-Insurance: coverage can help communities recover from disaster. In some developed countries (eg Japan) governments and insurance companies work together to provide insurance.
- NGOs - Especially important when local governments cannot afford a effective and rapid emergency response.
Involved in all stages of the Haard-management cycle
- Communites - Local people are the first responders
Crucial in delivering immediate healthcare and aid
In remote locations it can take days for aid to arrive so locals have to create temporary shelters and provide care themselves
Communities can be involved in long-term planning to reduce future vulnerabi
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definition of prediction:
knowing where and when a tectonic event will happen, with enough detail for it to be acted upon such as via evacuation.
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What strategies are used to predict earthquakes?
-currently no methods in predicting when/where earthquake will strike. But understanding plate tectonics allow scientists to know which areas - most at risk.
- eg. geologists know that most earthquakes happen along plate boundaries - areas that have had one are likely to have another- but they don't know exactly when they are likely to happen.
- Research today focuses on 'warning signs' called precursors - may suggest major earthquake is about to happen.
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What strategies are used to predict volcanic eruptions?
- Using equipment placed on a volcano and remote equipment (GIS mapping) scientists can monitor a volcano for signs that it might erupt- signs include:
- small earthquakes - as magma rises to surface - it breaks rock causing small earthquake - scientists can detect on seismographs
- changes to surface of volcano - as it pushes upwards, magma builds pressure causing surface of volcano to swell.
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What strategies are used to predict tsunamis?
- caused by underwater earthquakes - lack of way to predict earthquakes means there is no way to predict tsunamis before they occur - although possible to give early warning systems. (page 37)
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What are the different strategies to modify earthquakes and give an example:
- GIS mapping - identify where evacuation routes should be placed. Showed location an very rough population sizes of major towns and cities in Nepal. Areas affected by earthquake and locations of airports - helped aid agencies identify most affected by earthquake.
- Hazard resistant design and engineering defences - new buildings and structures (eg bridges), can be designed to resist ground shaking during earthquake. Existing buildings can be modified to make them safer eg. strengthening foundations.
eg. 2015 Nepal earthquake - GIS map showed info for relief operations.
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What are the different strategies to modify tsunami and give an example:
- land use zoning - areas at high risk from tsunami
- certain types of structures and facilities prohibited (nuclear power stations) - risk is damaged or critical for community functions (hospitals)
- some communities resettled - inland away from coast
- buildings elevated and anchored to their foundations, seawalls/ retaining sea walls
eg. Indian ocean tsunami - warning systems uses satellite communications technology - seismographs detected p waves off Japans north east coast.
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What are the different strategies to modify volcanoes and give an example:
- land use zoning - local government planners regulate how land in community is used, any settlements are limited, certain structures/ facilities will be prohibited (common in wealthy countries) communities resettled.
Diverting lava flows.
eg. Land surrounded by mount Taranki in New Zealand are divided into zones based on the likely type and level of damage from eruption.
Mount Etna (1983) successfully diverted lava away.
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Definition of mitigation:
practices used to describe actions and interventions that a community may take to reduce vulnerability in advance of a tectonic hazard event.
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Definition of adaption:
ways in which communities may be able to live with a tectonic hazard by making adjustments to reduce risk.
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What are the few steps that governments can take to reduce losses following a tectonic hazard?
- work with insurance companies to protect losses
- receive (and send) international and internal aid
- implement disaster response teams
- adopt international frameworks for disaster management.
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Seismicity definition:
the raw info about how frequently earthquakes affect a particular location.
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Seismic hazard definition:
the probability that a certain amount of risk will occur.
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Seismic risk definition:
The probability that a certain amount of risk will occur.
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What does it mean to modify the vulnerability?
Vulnerability is a key factor in determining the impact of a hazard, so making people less vulnerable will reduce the scale of the disaster
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what are the 4 different ways we can modify vulnerability?
(look at page from 9/5/25 to look at these)
- high- tech monitoring
- crisis mapping
- public education
- modelling hazard impact
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Geography paper 1 - Physical
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